Silly question - how does the IRS know what you've earned in the UK?

First of all, let me make it clear that I am not trying to avoid filiing taxes. I don't want any unnecessary misunderstandings.

Anyway, I know that I have to report any income I've earned in the UK to the IRS. My question is, how do I document what I've earned? A US employer would send me a W2 form. A British employer isn't going to provide me with any info for the US government. And from what I understand, British people don't file income taxes at all unless they are self-employed or have a very high income, the correct tax amount gets taken out of their paychecks automatically. So there isn't even a British equivalent of a W2. 

Also, what happens if I earn interest on a British bank account? How do I show the amount of interest to the IRS? I would get a 1099 form for a U.S. bank account.

You don't get any forms as the employment is British but the tax forms are American.  So, I guess to answer your question, they don't really know how much you make.  You could probably claim that you don't make anything over here.  Then again, the Inland Revenue keeps your tax records and if the US Treasury ever asked the Inland Revenue about your details, however unlikely, you could be in trouble, I suppose.

The same goes with interest earned, yes it is earned income so should be reported, I would assume, but there's no form because the IRS forms are only setup for US income sources.

Matt

You should get a P60 form every year (should be any time now).  It's just a statement of your earnings over the past year and is the UK equivalent of the W-2. 

Thanks. I would never even think about claiming nothing if I actually earned something.

Also, what happens if I earn interest on a British bank account? How do I show the amount of interest to the IRS? I would get a 1099 form for a U.S. bank account.

you'll get a statement of interest earned from your bank.

You should get a P60 form every year (should be any time now). It's just a statement of your earnings over the past year and is the UK equivalent of the W-2.

I've just asked my company when I'll receive this. They said not until the end of May or the beginning of June. Should I be worried about this? The form 2555 EZ (foreign income exclusion) asks for my company name and address, surely if they thought I was lying they could just write my company and ask, right?

If you won't get your P60 until after April 15, you can take advantage of the extended filing deadline offered to those of us who live overseas.  I believe there's a number to call -- have to find it myself as my taxes won't be done before the 15th!   

My DH has to file a UK tax return every year.  It is more complicated than the US tax form, well to me anyway.  I would file an extension like Lola said.